Even "space constrained" is arguable, depending on the context. We've had powerful, feature-packed phones no taller/wider than the screen and thin enough to fit in a tight pocket for years, and that's all anyone reasonably needs. But developers and gadgetphiles fetishize thinness to the point that devs are now actually removing important features, like headphone jacks and (on Android) removable batteries, to squeeze out a few more useless millimeters.
As long as those priorities remain, any power-per-volume improvements will be twisted around to serve pointless shrinkage rather than actually improving anything.
As long as those priorities remain, any power-per-volume improvements will be twisted around to serve pointless shrinkage rather than actually improving anything.